Tennessee Gov. William Haslam allowed a bill to pass Wednesday permitting teachers to discuss creationism and intelligent design as alternatives alongside evolution inside classrooms. Critics of the bill say it amounts to unconstitutional promotion of religion, while proponents of the bill say it simply grants academic freedom.

Both houses of the Republican-controlled Legislature passed the bill on March 29, sending it to the desk of the Republican governor. He neither signed nor rejected the bill, despite calls from both sides, over the last 10 days, so it went into effect.

I do not believe that this legislation changes the scientific standards that are taught in our schools or the curriculum that is used by our teachers, Haslam said in a statement. However, I also don't believe that it accomplishes anything that isn't already acceptable in our schools.

While he could have vetoed the bill, Haslam said there was no point as the Legislature had the votes to override.

The authors wrote the bill to help students understand, analyze, critique, and review in an objective manner the scientific strengths and scientific weaknesses of existing scientific theories. The bill also says that encourages students to question biological evolution, the chemical origins of life, global warming and human cloning.

While the bill prohibits teachers from introducing the topic of creationism or intelligent design, which is the belief that the universe was created by a deity, typically the Christian God, in class, it requires them to discuss them if the topic is raised.

But critics, who nicknamed the law The Monkey Bill after the 1925 Scopes Monkey Trial in which Tennessee prosecuted a high-school teacher named John Scopes for teaching evolution, which was against the law at the time, say the bill is an excuse to teach religion inside the classroom.

[The bill] states that teachers must be allowed to help students understand the 'weaknesses' of proven scientific theories such as evolution, the American Civil Liberties Union of Tennessee said in a statement. Using the phrase 'weaknesses' to describe scientific theories is typically code in the evolution debate to introduce non-scientific ideas like creationism and intelligent design into the science curriculum. Religion belongs where it prospers best-with individuals, families and religious communities -- not in the science classroom.

State Rep. Bill Dunn, who sponsored the bill, said its wording makes it clear it does not have a basis in religion.

The bill says it shall not be construed to instruct religion, he said. The bill is pretty clear. The Senate amendment laid right out that this will not change our state curriculum.

But Barry Lynn, executive director of Americans United for Separation of Church and State, told the Nashville Tennessean the true meaning is clear and it is designed to promote religion.

This has always been a way for teachers to interject their religious viewpoints if they contradict evolution, he said.

Dunn said he is not sure why there is such an uproar over the bill, since its intention is quite clear. He said the anti-religious are turning this into a religious issue, misconstruing facts and using the bill as an excuse to be mean and hateful.

The opponents of the bill are prejudiced, he said. I think they have an anti-religious bias and they use this bill as an excuse to spew their venom and hatred. And it is not based on the words of bill - it's based on the darkness in their hearts.